Method of removing static electricity.



W. H. CHAPMAN. METHOD OF REMOVING STATIC ELEGTRIGITY.. rrmonmn FILED JAN. 23, 1902,

983,53; Patented Feb.7,1 911.

" UNITED 's'rArEs PATENT OFFICE.

WILLIAM *H. GH APMAN,

F PORTLAND, MAINE.

METHOD OF REMOVING STATIC ELECTRICITY.

To all whom 'it may concern:-

Be it known that I, WILLIAM H. CHAP- MAN, a citizen of the United States of America, and a resident of Portland, county of Cumberland, State of Maine, have inventedcertairi. new and useful Improvements in Methods for Removing Static Electricity, of which the following is a specification.

My present invention has for its object the removal of static electrical charges from any material where the presence of such charges is objectionable, as in the drawing and spinning frames, in textile manufactories and it is an improved method of performing the process which is set forth in' my United States Patent No. (77,598dated Dec.

13, 1904. In that patent I showed a wire or other exposed conductor of small surfaces placed adjacent to the material and charged with an alternating potential by direct connection with a transformer or other'source of alternating currents. This arrangement is in many cases impracticable because the parts of the machine are too crowded to ad mit of space to place the charged wire and:

keep it sufficiently separated from other met allic masses to avoid sparking across and its presence is also objectionable in many he 0pcases because asin spinning frames eratives must frequently splice threads and would gettheir fingers in "contact with the' conductor, thus subjecting them to the spark that comes from such a charged conductor when touched.

My present invention consists ,in placing the material within. an alternating electro;

' surface,

' its function as inductor. "The fine wireac'tel conductor, being charges static field and placing a conductor of small like a fine steel wire also-within the alternatingelectrostatic field and pref- Cerably in proximity to the materiah The electrostatic field is obtained by placing an [insulated conductor of considerable surface at. any convenient point near the material to be treated and connecting, it with a source of high voltage alternating electricity. This designed merely to act by induction and establish an electrostatic field, it may be entirelyenveloped in a very'hea insulating covering without detracting i the least from its} efiiciency in performing upon by induction from the inductor dis'y first one kind of electricity and then the opposite kind into the air aroundq it, and yet/ it is always in a neutral condition as compared with persons and things around Specification of Letters Patent. Application Med January 23, 1908. Serial No. 412,281.

. the two. inductor becomes negative 1t causes a d1supon,

Patented Feb. '1, 1911' it and will not emit sparks when, touched and I have found that the wire under these conditions is just as efiicient in carrying out the process as though it were directly charged by conducting connection with the transformer, the opposing charges drawn into the air from it by the influence of the conductor become free to neutralize the materialfi i At the instant the inductor is positive it causes the wire to discharge negative into the air, forming for an -instant an air condenser in which a zone of air around the .wire is one plate and the inductor is the other plate, separated by an insulatinglayer of air. At the next instant when the alternating charge on the inductor has dropped to zero this bound electric charge is set free and if we assume the-material to have a positive charge the tendency to escape to the material and to neutralize itis much wgreater than is the tendency: to escape to v earth by reason of the fact that the tendency .to discharge between two bodies is pr0porthes'quare of the voltage between tional to But on the other hand when the charge of positive from the wire into the surrounding air which when liberated has more tendency to escape to earth than'lt has to go to the positive material. Thus the sum of cycles becomes a constant series of neutralizing impulses. In placing the small conductor with relation to the material acted I find that both must be within the electrostatic field with a body of unobstructed air between them, that is, any solid body rent is raised 'to a'high Volta e as for instance 10,000 volts,v which I have ound to be effective. The trans former is connected with a conductor c'of relativel. as a metal tube bar or ipjate. the conductor is so'forfned as to prevent discharge of e1 'tric ions into the air, that is, 1t must be f ree from projecting points or small surfaces; "It may be thoroughly insulated from an surrounding objects and it may be large surface such I The surface of inclosed or covered with insulatin material v sired points about the mac or parts of the machines.

to make it safe or unobjectionab e to persons coming in contact w1th it.

The material to be treated maybe any material charged with static electricity suc I as paper, yarn, roving, etc. I have here represented a web of pa er d passing adjacent to the conductor 6. he alternating charge applied to the coiiductor 0 creates an alternating electrostatic field which extends from a considerable distance around it in all di-' rections, its extent depending on the size, of the conductor and the tension of the charge. Within this electrostatic field the material is placed-or made to pass and also within the field is located a conductor of relatively small surfaces as a fine wire e connected with the ground or with abody of large static ca acity. The .wire is lacedpreferably ad acent to thematerial to be acted upon but it is more or less effective if laced anywhere within the electrostatic fiel provi ed there is no screen or obstruction interposed between the wire and the material, in which case the effect is destroyed. The conductor 6 may be of any size or shape and may extend over any size of surface as for instance it can be laced on the floor or above the same and thoroughl insulated and the wirescan then be lace at any deine so as to act on the material. By this method the fine wire which must be naked and cannot be insulated is rendered safe and free from sparkingeither from contact with persons be treated withinthe e .produced and placin asaaae In practice find it convenient to attach the fine wire to the insulating envelop of the inductor practically making it a art of the same structure sothat they'can e handled and located as one part.

1 I claim 1. The herein described method of removing static electricity from a body consistin of cha atively of char -'ng an'insulated conductor of relatively arge area the surfaces of said conductor being insulated with an alternating chargeqf high voltage placing the body to lectrostatic field thus a conductor of relatively small area wit in said fieldand adjacent to said body and connecting the same with the earth. In witness whereof I have hereunto setmy hand this 2d day of January, 1908.

WILLiAM Witnesses:

S. W. Barns, ELEANOR W. DENNIS.

H, CHAPMAN. 

